1. Field of the Invention
The present invention relates to objects which should be prevented from being forged and are to be checked for authenticity, such as important documents, securities, paper money, merchandise bonds and other coupons, checks, traveler's checks, bank cards, credit cards, prepaid cards, admission tickets for various entertainments and parties, passenger tickets for various vehicles and aircrafts, and betting tickets for publicly-managed gambling (e.g., speedboat, bicycle, and horse races), and a method for manufacturing the same.
2. Description of the Related Art
A checking method and apparatus utilizing microwaves are known in the art as measures for checking the authenticity of documents or the like, as described in Jpn. Pat. Appln. KOKAI Publication No. 5-270181 and PCT National Publication No. 63-501250 (i.e., U.S. Pat. No. 4,820,912). In this prior art method or apparatus, microwaves are applied to a large number of metallic wires, such as stainless-steel wires, which are distributed at random in a document or the like, and a proper digital mark corresponding to a response microwave bundle is recorded in a suitable region of the document according to specific rules. In checking the document for authenticity, the microwaves are applied to the document, and the digital mark is collated with the response microwave bundle. If the mark and the microwave bundle agree with each other, it is concluded that the document is authentic.
Checking means which utilizes microwaves, such as the one used in the conventional apparatus described in the aforesaid publications, is liable to be influenced by external noises as it measures the response microwave bundle, so that its signal-to-noise ratio (S/N ratio) is low. Moreover, the prior art apparatus, which oscillates microwaves, may possibly constitute a source of noises. In general, furthermore, microwave transmitters and receivers are large-sized and expensive.
In the case where metallic wires are embedded in a thin object, such as paper, there is a possibility of the wires being exposed in the surface of the object. If this occurs, the metallic wires are so conspicuous that the security cannot be maintained. In the case where the object containing the metallic wires is cut into pieces of a desired size by means of a cutter, the wires may partially project from cut edges of the object, or the cutter life may be shortened considerably. Moreover, the metallic wires constitute a hindrance to satisfactory printing or coloring, and may rust in some cases.
When the object is bent, the metallic wires may possibly be broken or crooked, thereby projecting from the surface of the object, or the distribution of the metallic wires peculiar to the object may become different from the original state, thereby making code collation impossible.
In the case of a pari-mutuel ticket for a horse race, data including the serial number of the ticket purchased by a bettor, post position numbers, bet numbers, etc. are printed in figures on the obverse of the ticket. Also, these indication data are encoded according to specific rules, and are magnetically recorded as magnetic data in a magnetic layer on the reverse of the ticket. In this case, the magnetic data are read by means of a promoter's ticket reading apparatus when repayment is claimed after the race. Thereupon, the serial number, post position numbers, bet numbers, etc. are read, and a share for winning bets is paid.
Alternatively, according to some other betting tickets for publicly-managed gambling, a bar code is arranged in a predetermined position in the ticket instead of using the magnetic data. In this case, illegal or wrongful acts, such as alteration of data, are prevented by recording post position numbers, bet numbers, etc. in the bar code.
In the case of the aforementioned pari-mutuel ticket, the indication data, including the post position numbers, bet numbers, etc., are printed in figures on the obverse of the ticket, while the magnetic data associated with the indication data are recorded in the magnetic layer on the reverse. The ticket of this type is somewhat advantageous in preventing malicious alteration or reproduction, since the details of the magnetic data are invisible. In this case, however, the magnetic layer entails a very high cost for each ticket. For example, a ticket having the magnetic layer may be several times as expensive as one which uses a bar code. If the ticket is provided with the magnetic layer, moreover, then it will contain too much magnetic material. Accordingly, the ticket will not be able to be reused as reclaimed paper, and besides, will involve problems concerning incineration. Thus, disposal of used tickets is a serious problem.
In some alternative betting tickets for publicly-managed gambling, the indication data, including the post position numbers, bet numbers, etc., are printed in figures on the obverse of the ticket, and cipher codes associated with these indication data is recorded in the form of a bar code on the ticket surface. In this case, however, the indication data and the bar code are visible. Even though the post position numbers, bet numbers, etc. are enciphered and represented in the bar code, therefore, a key to falsification of the bar code may possibly be given to permit illegal use of the ticket as a winning one when rules for enciphering are revealed. If winning tickets are identified by the bar code only, moreover, there is a possibility of duplicates (or so-called dead copies) of the winning tickets being made.